The Gardeners Almanac

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Lythrum

Common name: Purple Loosestrife

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Week Numbers

Basal Cuttings

Coldframe

Collect Seed

Compost

Deadheading

Division

Heating

Planting out

Pricking out

Seed sowing

Overview:

Single panicle

Lythrum
Flowerhead

Panicles of purple flowers

Lythrum

Lythrum - Purple Loosestrife is native to Europe and Asia.


This hardy upright, semi-woody, bushy herbaceous perennial and is extremely adaptable to a wide range of conditions, and will grow almost anywhere except in full shade.

This characteristic makes them a useful subject for the borders of water features.

They grow to around 600-750mm (24"-30") high, and their purple to magenta on long spikes flower from late June until October.


Lythrum can be a very invasive plant, in fact they can be so invasive to the point that they can be considered a weed in some areas.

For this reason deadhead regulary to keep it from self seeding.


Cultivation:

Week 14:

Sow in pots / trays of seed compost and germinate at a temperature of 16°C (60°F)

Named varieties do not come true from seed.

Prick out the seedlings when large enough to handle in 75mm (3") pots of potting compost and grow on in a coldframe until planting out time.


Week 18:

Take 75mm (3") long basal cuttings, and insert in pots of 50-50 in equal parts (by volume) peat and sand.

Place in a coldframe to root in a cold frame.

When rooted, treat as seedlings.

Week 40:

Plant out 500mm (18") apart in ordinary garden soil in sun or semi-shade.

These plants will thrive near water, in a damp / wet semi-shaded situation.


Week 42:

Cut back plants to ground level.

Plants can also be divided at this time.